ABSTRACT A rapid demographic transition underway in low and middle-income countries (LMIC) will substantially increase the number of older adults suffering from Alzheimer?s disease and related dementias (ADRD) so that by 2030 more than 2/3 of all persons suffering from ADRD worldwide will reside in LMIC. Consequently, there is growing recognition in Vietnam and other LMIC that ADRD poses a major public health issue and the importance developing scientific evidence and research capacity to meet this challenge, including developing effective community-based support programs for family caregivers of persons with Alzheimer?s disease. Building on an established cross-national partnership between investigators in Vietnam and two HIC (US and Australia), the overall goals of this project are to test the efficacy of a community-based program to support Alzheimer?s family caregivers in Vietnam and to strengthen research capacity through development of a national Vietnam ADRD research network. To achieve these goals, we will build directly on the accomplishments of our planning grant. We now have in place a robust and effective collaborative relationship between investigators in HIC (US and Australia), the Vietnam National Geriatric Hospital (NGH), and the Vietnam Ministry of Health (MOH). Our research team has culturally adapted, implemented and tested the feasibility and preliminary efficacy of a community-based family ADRD caregiver intervention model (REACH VN) in a pilot cluster RCT of 60 family caregivers. Preliminary results of our pilot cluster RCT show strong evidence of both feasibility and preliminary efficacy. We now propose to test the efficacy of the REACH VN in a larger cluster RCT embedded in the community using a Stage III clinical trial design coupled with a formative evaluation using the RE-AIM framework to inform future implementation. We will also enhance ADRD research capacity more broadly in Vietnam by establishing a national network of researchers and creating a linked pilot grant program to provide mentoring and funding to meritorious scientists conducting ADRD research on family caregiving and other issues of high relevance to policy makers. Specific goals of this project are to 1) test the efficacy of REACH VN in Vietnam in cluster randomized controlled trial of 32 clusters (350 families), 2) identify key barriers and facilitators of REACH VN implementation in a community setting through a formative evaluation conducted in parallel with the cluster RCT, and 3) strengthen and build Vietnam national capacity in caregiving and other ADRD research through the creation of a network of researchers and a program of mentoring and pilot support.